Haematological factors associated with proliferative retinopathy in sickle cell-haemoglobin C disease.

In a selected sample of patients with sickle cell-haemoglobin C (SC) disease, proliferative retinopathy (PSR) occurred in 90/243 (37%) patients, developed most frequently between the ages of 20 and 30 years, and affected 68% patients aged 45 years or over. Comparison of haematological indices in patients with and without PSR, after age-related effects were allowed for, indicated significant relationships with high mean cell volume in males and with low fetal haemoglobin in both sexes. A highly significant relationship with total haemoglobin level in males (as previously reported in SS disease) was shown in SC disease to be entirely secondary to a strong age-related trend in haemoglobin level.